Welcome to the rest of the world, guys - yes, not everyone uses dollars... I can't believe this is shocking to you.
As a guide, so you shouldn't make a similar mistake in the future, here are a few things about the UK that you ought to know. In addition to having had a different currency to you chaps for quite some time, here in the UK we also use a different television standard, use the metric scale sometimes (and have bigger pints than you when we don't), have a different voltage for mains electricity using different plugs, different telephone sockets, vote for our own government (admittedly, just a puppet government run by GWB) and you cannot buy beef jerky. It is also worth noting that, despite Europe looking like a reasonably insignificant smear on a map, it is made up of a number of independent states, and all these things mentioned are different again on mainland Europe - currency, TV standard, plugs, weights and measures, pints, telephone sockets, governments. All except the beef jerky - that remains universally unavailable outside the US.